MENEGASHA, Ethiopia — On a wooded hill near Ethiopia’s capital of Addis Ababa, bits of red clay litter the ground next to glittering flakes of obsidian. Nearby, half-buried stones are arranged in a line. On the other side of the hill, a rectangular stone slab appears to have been broken in half.

For archaeologists like Samuel Walker and his colleague Ayele Tarekegn, it’s evidence that this was once the site of a medieval city. The bits of clay are shards of pottery, the flakes of obsidian were tools used by artisans to work leather, and the stones probably were once the walls of churches and palaces.

“It’s unbelievable that it’s here,” Walker said. “When I saw this, I thought this is just the tip of the iceberg — everywhere we dig, we find stuff.”

Archaeological digs are rare in Ethiopia, despite its wealth of potential sites. “It’s a poor country, and archaeology is a very expensive subject,” said Ayele, who is trying to develop the field in the country. “It’s all to do with money and developing the expertise, the personnel and the manpower.”

There are plans to organize a conference of donors in January to develop Ethiopian archaeology, preserve existing sites and maybe explore new ones. More investment in the field could shed light on little-known parts of the country’s history. Perhaps more important, it may bring clarity to some of the modern debates roiling Ethiopia as it transitions from oppressive authoritarianism to a freer society in which its many ethnic groups can make their voices heard.

When reformist Prime Minister Abiy Ahmed came to office in April, he sought to open up the country by inviting back exiled rebels, releasing political prisoners and ending long-running government repression.

His changes have been enormously popular, but they have also been accompanied by unrest. With more than 80 ethnic groups competing for land and influence, animosities suppressed by the old government have risen to the surface, especially between the two main groups: the Oromo — the largest in the country, but one that has long felt marginalized — and the Amhara, the historical rulers of much of Ethiopia.

Both groups are sparring over which can lay claim to the capital, Addis Ababa. The Oromo say it was their land before Emperor Menelik II, the ruler of the Amhara-dominated Abyssinian Empire, took it away to found the city in 1887. The Amhara say it was part of their empire long before the Oromo migrated there.

The remnants of the cities that Walker has found could help answer these questions. Suddenly, history and archaeology have become political.

While there are medieval ruins in Ethiopia, not much is known about the period. A map of the region drawn in 1450 by a Venetian monk showed Ethiopia covered in cities like the one Walker found. “The material culture we have surviving from that time shows significant direct importing of religious and cultural material from as far away as France and Flanders. It is incredibly wealthy and artistically articulate,” said Verena Krebs, an expert on medieval Ethiopia at Germany’s Ruhr-University Bochum.

But when the Portuguese arrived in the 16th century, they found a place with few permanent settlements. So what happened in the intervening years? War. To be precise, religious wars.

In the 1520s, Ethiopia’s Muslim vassal states rebelled against the Christian hegemony. Their forces descended on what was then the Abyssinian Empire and sought to destroy it, burning palaces, monasteries and trading posts and carrying off untold riches in gold and silver.

With Portuguese help, the Ethiopians defeated the Muslims, but the two adversaries were left exhausted. The Ethiopian forces retreated from the area around modern-day Addis Ababa; into the vacuum came the Oromo people from the south. They settled the area and worked the land as farmers and herders until most traces of the ruined cities had vanished.

Such discoveries could remind modern Ethiopians of their country’s past as a wealthy, cosmopolitan trading empire with contacts around the world. Abiy, the new prime minister, has said he wants to restore the country’s links with the outside world, especially its international trade.

As anger between Ethiopia’s many peoples reaches a fever pitch — some 1.4 million people have been displaced this year by violence across the country — archaeology may provide a timely warning about how war, fanaticism and ethnic rivalry destroyed Ethiopia in the past.